Along with the rapid development of display technologies, capacitive built-in touch screens have been gradually used in people's daily life. An existing capacitive built-in touch screen includes an additional touch sensor directly arranged on an existing array substrate. Usually, the touch sensor uses two bar-like electrodes, which intersect each other in different planes, as a touch scanning line and a touch sensing line, respectively, and a touch sensing capacitor is formed at an intersection of the two electrodes, which however will result in a complex process and a low aperture ratio. A touch scanning signal is applied via the touch scanning line, and a touch sensing signal sensed by the touch sensing line through the touch sensing capacitor is detected. During this procedure, if a human body contacts the touch screen, an electric field of the human body will be applied to the touch sensing capacitor so as to change the capacitance value of the touch sensing capacitor, thereby to change the touch sensing signal detected by the touch sensing line. As a result, it is able to determine a position of a touch point in accordance with the change of the touch sensing signal.
Another existing capacitive built-in touch screen includes gate lines or data lines arranged on the array substrate as the touch scanning line and the touch sensing line. However, the gate line and the data line are also used for a display function, so it is required to achieve the display function and a touch function within different time periods. As a result, a charge time for pixels or a display refresh rate will be reduced.